This invention relates to an agricultural machine such as a mower conditioner, and more particularly to a mechanism for adjusting the elevation of a cutting mechanism forming a part of a mower conditioner.
An agricultural harvester such as a mower conditioner typically includes a frame or trailer carrying a pair of ground-engaging wheels, and a header pivotably mounted to the frame. The header carries a crop cutting mechanism, such as a sickle bar cutting mechanism or a disc-type cutterbar, and conditioning rolls are typically mounted to the header rearwardly of the cutting mechanism for conditioning crop material cut by the cutting mechanism. The header is typically mounted to the frame for pivoting movement about a horizontal pivot axis, located generally toward the lower extent of the machine. The header is also connected to the frame at a location above the pivot axis. In the past, it has been known to interconnect the header with the frame utilizing a turnbuckle-type arrangement. With an arrangement such as this, the distance between the header and the frame can be adjusted above the pivot axis, so as to adjust the angle of the header relative to the frame which results in adjustment of the elevation of the cutting mechanism relative to the ground. While this arrangement generally functions satisfactorily, the turnbuckle arrangement requires use of a wrench to adjust the spacing between the header and the frame, and the adjustment process is relatively time consuming.
It is an object of the present invention to provide a height adjustment mechanism for the cutting mechanism of an agricultural harvester, which is user friendly and which provides quick and easy adjustment in the height of the cutting mechanism. Another object of the invention is to provide such a height adjustment mechanism which is relatively simple in its components and assembly, thus requiring little if any additional manufacturing costs. Yet another object of the invention is to provide such a height adjustment mechanism which functions in a similar manner to prior art mechanisms yet which is easy to use and provides accurate height adjustment which is readily visible by an operator.
The invention is adapted for use in combination with an agricultural harvester having two sections which are pivotably interconnected for movement about a substantially horizontal pivot axis. One of the sections is in the form of a frame to which a pair of groundengaging wheels are mounted, and the other of the sections is in the form of a header which carries a crop cutting mechanism and which is mounted for pivoting movement to the frame about a header pivot axis. In accordance with the invention, a link arrangement is interposed between the header and the frame at a location spaced from the header pivot axis, so as to adjust the position of the header by varying the angle of the header relative to the frame. The link arrangement includes a pair of link members connected to each other. A first one of the link members is mounted to the header and a second one of the link members is mounted to the header and to the frame. In a preferred form, the second link member is pivotably mounted to the frame, and the first and second link members are pivotably interconnected with each other, such as by means of a pivot pin to which each of the link members are pivotably mounted. An adjustment member is interposed between the header and the first link member, for varying the position of the header relative to the link arrangement to thereby adjust the position of the header relative to the frame. In a preferred form, the adjustment member is in the form of a threaded shaft engaged with the header and threadedly engaged with the second link member. The second link member may be in the form of a clevis, including a pair of side members and an end member defining a threaded passage which receives the threaded shaft. Guide structure is provided for guiding movement of the header relative to the link arrangement. In a preferred form, the guide structure consists of a pair of spaced guide plates, each of which has a guide slot formed therein. The pivot pin, which interconnects the first and second link members, is received within the guide slots, and the slots define spaced ends which engage the pivot pin to limit the range of movement of the header relative to the frame. The guide members are preferably mounted to the header. A handle arrangement is preferably interconnected with the threaded shaft, for engagement by a user to enable the threaded shaft to be turned. The handle arrangement includes an axial portion extending from the threaded shaft, in combination with a transverse portion engageable by a user to turn the axial portion and to thereby rotate the threaded shaft. The header preferably includes a hood movable between an open position and a closed position. In its open position, the hood provides access to the handle to enable a user to grasp the handle transverse portion and to rotate the threaded shaft to vary the elevation of the cutting mechanism. When the hood is open and the user is in a position so as to turn the handle, the user can readily view the cutting mechanism so as to ensure that the cutting mechanism is positioned at a desired elevation relative to the ground. When the hood is in its closed position, the hood overlies the handle transverse portion so as to prevent the handle from turning and to thereby ensure that the cutting mechanism remains at the desired elevation.
The invention also contemplates an improvement in an agricultural harvester, substantially in accordance with the foregoing summary.
Various other features, objects and advantages of the invention will be made apparent from the following description taken together with the drawings.